BASE_PKGS := alpine-keys alpine-baselayout
BOOT_HOST := 203.0.113.1
ROOT_DIR:=$(shell dirname $(realpath $(firstword $(MAKEFILE_LIST))))
PROTO := http
MIRROR := $(PROTO)://$(BOOT_HOST)/alpine/extended

all: base packages files commands build-overlay

base:
	@echo " * Building Base Image..."
	@ping -qW 1 -c 1 $(BOOT_HOST) >/dev/null || ( echo " -- Unable to reach $(BOOT_HOST)" && exit 1 )
	@mkdir -p tmp base
	@echo " -- Gathering base package info"
	@wget -q $(MIRROR)/x86_64/ -O tmp/alpine-packages.html
	@for pkg in $(BASE_PKGS); do \
		pkgver=$$(grep \"$$pkg tmp/alpine-packages.html | egrep -o [0-9]+\.[0-9]+[0-9.]*-r[0-9]+ | uniq); \
		wget -q $(MIRROR)/x86_64/$${pkg}-$${pkgver}.apk -O tmp/$${pkg}-$${pkgver}.apk; \
		done
	@echo " -- Create Base Layout"
	@tar xzf tmp/alpine-keys-*.apk -C base 2>/dev/null
	@tar xzf tmp/alpine-baselayout-*.apk -C base etc/shadow etc/hosts etc/group etc/passwd 2>/dev/null
	@echo " -- Setup Init"
	@for runlevel in boot default shutdown sysinit; do \
		mkdir -p base/etc/runlevels/$$runlevel; done
	@for initd in bootmisc hostname hwclock modules sysctl syslog networking; do \
		ln -s /etc/init.d/$$initd base/etc/runlevels/boot/$$initd; done
	@for initd in devfs dmesg hwdrivers mdev modloop; do \
		ln -s /etc/init.d/$$initd base/etc/runlevels/sysinit/$$initd; done
	@for initd in killprocs mount-ro savecache; do \
		ln -s /etc/init.d/$$initd base/etc/runlevels/shutdown/$$initd; done
	@sudo rm -rf tmp

.PHONY: packages
packages: base
	 @test \! -d target && echo " * Cloning base to target..." \
		 && sudo rsync -raH base/ target || true
	 @if [ \! -f packages ]; then \
		 echo " * No packages to Install"; \
	elif diff -q packages target/etc/apk/world 2>/dev/null >/dev/null; then true; \
	else \
		echo " * Updating apk/world file..."; \
		cp packages target/etc/apk/world; \
	fi

.PHONY: files
files: packages
	@echo " * Copying Files..."
	@sudo cp -rv files/* target

.PHONY: commands
commands: files
	@echo " * Running Commands..."
	@echo " -- Setup local start"
	@ln -s /etc/init.d/local target/etc/runlevels/default/local 2>/dev/null || true

.PHONY: build-overlay
build-overlay: commands
	@echo " * Building Overlay..."
	@mkdir -p tmp output
	@sudo rsync -raH target/ tmp/overlay
	@sudo chown -R root:root tmp/overlay
	@cd tmp/overlay; sudo tar czf $(ROOT_DIR)/output/apkovl.tar.gz .
	@sudo rm -rf tmp

clean:
	@echo " * Cleaning Up"
	@sudo rm -rf base tmp output target